Hill's Prescription Diet z/d Skin/Sensitivities is a dry dog food for dogs with confirmed food allergies or severe food sensitivities. The hydrolysed protein source is broken into pieces too small to be recognised by the immune system, eliminating allergic responses to common dietary proteins.

Hydrolysed chicken liver provides complete amino acid nutrition without the molecular size needed to trigger an immune reaction. The recipe deliberately excludes common allergens — no whole protein sources, single carbohydrate source, no gluten — making it suitable for elimination diet trials and long-term feeding of confirmed food-allergic dogs. Added omega-3 fatty acids support skin and coat health affected by chronic inflammation.

Vets use z/d as the gold-standard food allergy diagnostic — a strict z/d-only trial for 8-12 weeks identifies food-driven skin or digestive symptoms. Owners often continue feeding it long-term once they see the difference: less itching, fewer ear infections, settled stools.